Combobox Not Responding - Imbedded Directly In Worksheet

I am working on a macro that runs when a combobox is clicked. The combobox is imbedded directly in the worksheet, not in a form.

Basically, the user clicks the down arrow on the combobox, selects one of the available choices, and the choice selected is written to the spreadsheet - each time the selection is made, it is written to a successive row in the spreadsheet - keeping track of every selection made.

The macro works, mostly. But problem is that if the user repeats a selection in the combobox (makes a choice, and then in the next cycle makes the same choice) the macro doesn't run - nothing happens.

Here is the code:

Private Sub ComboBox1_Change()
i = Cells(2, 4) ' value in cell D2
Cells(i, 6) = Cells(4, 9) ' selected value from cobobox stored in cell I4
' This value copied to column F - successive rows
i = i + 1 ' counter to increment row for next value
Cells(2, 4) = i ' Update cell D2 with new i value
End Sub